ONI-CoV2RNA: A single step imaging-based assay for direct detection of SARS-CoV-2 RNA

对SARS-CoV2的诊断检测是应对新冠肺炎大流行的公共卫生对策的核心，有助于隔离无症状病例，从而抑制社区传播。随着经济和娱乐活动的恢复，新冠肺炎检测变得越来越普遍，例如，现在旅行到许多国际目的地都要求检测结果为阴性。几乎所有的SARS-CoV-2诊断试验都有两种方法：RT-PCR和侧向流动抗原试验。RT-PCR检测灵敏度高，但在依赖复杂传递网络的中央设施中进行，需要几个小时的处理时间，而且周转时间较慢(~24小时)。侧向血流试验由患者进行，因此结果迅速返回(30分钟)，然而，该试验不太敏感，仅检测到RT-PCR阳性病例的60%(Cochrane Revision，2021)。RT-PCR和侧向血流测试需要鼻咽拭子，这让人不舒服，如果不是由训练有素的专业人员收集，可能会得出不一致的结果。ONI正在开发一种新的方法，通过省去耗时和昂贵的样本制备步骤，使用广泛可用的试剂，使样本分析自动化、快速和安全，从而在10分钟内检测出SARS-CoV-2和其他呼吸道病毒。我们的一步病毒检测方法将允许直接检测和区分唾液中的SARS-CoV-2和其他病毒，而不需要鼻咽拭子。该检测将在ONI的新成像设备上运行，该设备具有专门为该检测设计的独特的桌面格式和易于使用的工作流程。我们将与伦敦帝国理工学院的合作伙伴一起，对新冠肺炎临床拭子样本进行现有测试的并排验证，并通过伦敦IVD合作社评估其易用性。然后，我们将与药物发现弹射器(MDC)-灯塔实验室的合作伙伴一起优化仪器的可用性，以便非专业人员可以轻松操作该设备。我们的检测将不再需要高度封闭的设施和具有自动化分析操作的专业人员，便于在分散的临床和非临床环境中使用。我们将聘请监管机构支持机场和公司的检测，我们紧凑而快速的平台将使在几分钟内检测到无症状携带者中的SARS-CoV-2和其他呼吸道病毒，有助于减少感染传播，将进一步的经济损失降至最低，并允许控制未来出现的病毒。Oni-VirusDx检测有可能在英国范围内实现快速、分散的单步病毒测试。

Diagnostic testing for SARS-CoV2 is at the centre of the public health response to the COVID-19 pandemic, facilitating the isolation of asymptomatic cases thereby suppressing community transmission. COVID-19 testing is becoming ever more widespread as economic and recreational activities resume, for example, a negative test result is now required to travel to many international destinations. Two methods account for almost all SARS-CoV-2 diagnostic tests: RT-PCR and lateral flow antigen tests. RT-PCR tests provide high sensitivity but are performed in centralised facilities that depend on complex delivery networks, take several hours to process and have slow turnaround times (~24 h). Lateral flow tests are performed by the patient so the result is returned quickly (30 min), however, the test is less sensitive, catching only 60% of cases that were positive by RT-PCR (Cochrane review, 2021). RT-PCR and lateral flow tests require a nasopharyngeal swab, which is uncomfortable to perform and can give inconsistent results if not collected by a trained professional. ONI is developing a novel method to detect SARS-CoV-2 and other respiratory viruses in under 10 minutes by removing time-consuming and costly sample preparation steps, using widely available reagents and making sample analysis automated, faster and safer.Our single-step virus detection assay will allow direct detection and differentiation of SARS-CoV-2 and other viruses in saliva without the need for a nasopharyngeal swab. The assay will run on ONI's new imaging device, with a unique desktop-format and easy-to-use workflow designed specifically for this assay. Together with partners at Imperial College London we will perform side-by-side validation with existing tests on COVID-19 clinical swab samples and assess its ease of use through the London IVD Cooperative. We will then optimise the instrument’s usability with partners at Medicines Discovery Catapult (MDC)-Lighthouse Labs so that the device can be easily operated by non-specialists. Our test will remove the need for high-containment facilities and specialised personnel with automated assay operation, facilitating its use in de-centralised clinical and non-clinical settings. We will engage regulatory bodies to support testing at airports and companies, where our compact and rapid platform will allow detection of SARS-CoV-2 and other respiratory viruses in asymptomatic carriers in a few minutes, helping reduce infection spread, minimising further economic losses and allowing control of future emerging viruses. The ONI-VirusDx assay has the potential to allow rapid, de-centralised single-step virus testing UK-wide.